The study included 218 patients with heart failure (HF) on the background of post-infarction cardiosclerosis. 109 (50.0%) patients with AIT received LT due to hypothyreosis in past. These patients intake LT during 2 years before included in the study and have euthyreosis. Whether the levels of TSH, T3f, T4f, T3r were determined. Echocardioscopy and ultrasound examination of the thyroid gland were conducted. We studied the course of heart failure for 2 years.
Patients who used LT, comparing with patients without this drug, had smaller dimensions (EDD and ESD) and volumes (ESV and EDV) of left ventricle (LV) and 22.9% greater LV ejection fraction (EF) (p = 0.0001), as well as higher low serum NT-proBNP level (26.3%, p = 0.009). In the subgroup of patients taking LT at a dose of 0.1 to 0.69 μg / kg, LVEF did not differ from patients without this tritment. At a dose of 0.7-1.19 μg / kg, LVEF is higher compared with that of patients who did not take LT (by 37.9%) and patients who took LT at a dose 0.1 - 0.33 mcg / kg (36.9%). LVEF was the highest in patients taking LT at a dose of> 1.20 mcg / kg. The use of LT for 2 years reduces the risk of re-hospitalization (RH) due to decompensation of heart failure (Odds ratio = 0.490 (0.281-0.857), p = 0.018) and a tendentious decrease in the risk of combined endpiont achieving (by 27.9%, p = 0.074). The ROC analysis showed that the risk of RH in patients with heart failure due to decompensation of the disease decreases with the use of LT at a dose of> 0.53 μg / kg (sensitivity - 56.62%, specificity - 60.98%, p = 0.016).
The use of LT in patients has a dose-dependent positive effect on LVEF. The largest LVEF is observed in patients taking the drug at a dose of> 1.2 mcg / kg. The use of an LT dose of> 0.53 mcg / kg leads to a significant decrease in the frequency of re-hospitalization due to decompensation of heart failure during 2 years.
Key words: heart failure, autoimmune thyroiditis, levothyroxine, ejection fraction, course of the disease.